MR: I used to assist Danilo [Gwen Stefani's steady stylist] on color jobs, and when he was too busy, he'd send me models who needed drastic changes — Carolyn Murphy, Eva Herzigova. I kept their hair in good condition. From there, I got the actresses who wanted to go from dark to light for a part.

MC: What was your favorite transformation?

MR: Making Jennifer Connelly blonde for the upcoming What's Wrong with Virginia. She looks so interesting and beautiful as a blonde. But her hair is delicate, so when it came out perfect, I was over the moon.

MC: How do you keep colored hair healthy?

MR: I like to do drastic changes over several days or weeks. Giving hair a break between chemical processes improves its condition and elasticity.

MC: New York vs. L.A.: Are the blondes different?

MR: If a New York client asks for California blonde, that means more of a buttery shade. L.A. taste runs warmer because you're naturally a little more tan, so you don't want your hair color to be too flat.

MR: No, I encourage it! To save money, I've told clients to get big changes at the salon and do subtle ones at home. A highlighting kit can give a sun-kissed look. Just put your hair into a ponytail, then pull out a few strands around your face and at the ends.

MC: Any other brightening tricks for summer?

MR: When I had light-brown hair, I'd spritz it with a mixture of vodka and lemon juice at the beach for blonde-y highlights. I think it's mostly the lemon juice, but that combination seems to work best.

MC: You haven't always been a blonde?

MR: I did reddish glosses in high school because I wanted to be like my Irish grandmother. She was my biggest role model. In my early 20s, I was obsessed with Isabella Rossellini in Death Becomes Her, so I dyed my hair dark. After that, I colored it the exact neon orange as Milla Jovovich in The Fifth Element — I even had the dreads! Now people recognize me as a blonde. It took two years to get this perfect platinum.

MC: It sounds like a lot of maintenance!

MR: I have my standing appointment every four weeks, which I pay for, so I fully understand that I'm eating my clients' pockets. I'm really addicted to my colorist, Bryan Thomson-DiPalma. He'll be working with me at the new salon [Marie Robinson Salon, 155 Fifth Avenue, New York, marierobinson.com], which will make it easier.